Wax substituted diaryl dithiophosphoric acids and salts thereof



Patented Dec. 26, 1944 WAX SUBSTITUTED DIARYL DITHIOPHOS- PHORIC ACIDS AND SALTS THEREOF Elmer W. Cook, New York, N. Y., and William D.

Thomas, Jr., Stamford, 001111., assignors to American Cyanamid Company, New York, N. Y., a corporation of Maine No Drawing.

16 Claims.

This invention relates to new chemical compounds and their preparation, and more particularly to wax substituted diaryl dithiophosphoric acids and salts thereof.

The compounds of the present invention to be described and claimed herein byus may be represented by the general formula,

Application October 17,1941, Serial No. 415,410

in which R represents a wax substituted aryl radical, M is hydrogen or a salt-forming radical and n is the valence of-hydrogen or of the salt-forming radical.

These compounds have a strongly polar group V and high molecular weight hydrophobe groups and accordingly show detergent properties. As the wax substituted aryl radicals contain long chain alkyl groups the compounds are readily soluble in oils making them particularly valuable in the petroleum field. They may be added to *lubricating oils as detergents to disperse sludge thereby preventing varnish formation, ring sticking, etc. They also show antioxidant properties and are useful in lubricating oils to prevent sludge formation and bearing corrosion. Our compounds have also been found to be of value as pour point depressants in lubricating oils. Being water insoluble and polar in character they are valuable in the preparation of slushing oils. Because of their sulfur and phosphorus content they may be advantageously added to hypoid gear R-O SE from which it is seen that 1 moleof PzSs reacts with 4 moles of the wax substituted hydroxyaromatic compound with the elimination of one mole of Has. The reaction may be brought to a satisfactory degree of completion in one hour but extended heating, for example more than five hours, should be avoided since the product tends to 'form thio-anhydrides by the elimination of 55 strontium and barium may be introduced by men.

H28. The wax substituted diaryl dithiophosphoric acid thus formed is a liquid and ma be decanted from any unreacted P285. Suitable salts of these wax substituted diary] dithiophosphoric acids may be prepared by simple neutralization of the compound with salt-forming bases or by double decomposition with its sodium salt.

The wax substituted hydroxyaromatlc compounds to be reacted with P285 are prepared in known manner by condensation of a halogenated wax, such waxes being generally characterized by long alkyl chains having at least 20 carbon atoms, with a hydroxyaromatic compound in the presence of a Friedel-Crafts catalyst. The chlorinated waxes used in such syntheses are generally those prepared by chlorination of waxes derived from petroleum which are usually mixtures of long chain aliphatic compounds having 22-26 or more carbon atoms in the chain. The hydroxyaromatic compounds may have one or more by. droxy groups per molecule and may also be of the single, double, or triple ring type. We prefer to.

have two or more without unduly afiecting its desirable properties. In addition to having long chain alkyl groups substituted in one or more of the positions in the ring the wax substituted hydroxy aromatic compounds may also have other radicals attached thereto such as the shorter chain alkyl, aryl, aralkyl and alkoxy groups.

Among the hydroxyaromatic compounds which may be reacted with chlorinated waxes to provide suitable intermediates are phenol, cresol, xylenol, hydroxy diphenyl, hydroxy diphenyl ether, hydroxydiphenyl monosulfide, methyl hydroxy diphenyl, benzyl phenol, a and 13 naphthol, methyl or and ,B naphthol, benzylnaphthol, guaiacol, chiorphenol and phenol-formaldehyde condensation products in their lower stages of polymerization. Since the preparation of wax substituted hydroxyaromatic compounds i well known further discussion of these products and their preparation appears to be unnecessary.

The wax substituted diaryl dithiophosphoric acids may be made into salts by simple neutraliforming radicals including those of nickel, aluminum, lead, mercury, cadmium, tin, zinc, magnesium, sodium, potassium, ammonium, calcium,

32 parts by weight of phenol and 150 parts by weight of chlorinated wax, containing 16% chlorine, weredissolved in 50 parts by volume of A. S. T. M. precipitation naphtha. The solution was then cooled and 16 parts by weight of anhydrous aluminum chloride were added with stirring. While continuing the stirring the mixture was slowly heated and refluxed for three hours. The mixture was then cooled and treated with 150 parts cool dilute hydrochloric acid. 150 parts by volume of naphtha was then added and the solution extracted times with'water. The aphtha was then evaporated leaving a wax substituted phenol.

l55'parts by weight of wax s bstituted phenol was stirred and heated with 2 parts by weight of P285. for 2.5 hours at 140-14'5 C. The resulting brown-colored liquid was decanted from a small amount of unreactedl 'ass and was found to consist of wax-substituted diphenyl dithiov pl osphoricacidotthe formula 150 parts by weight of the above di(wax phenyl) dithiophosphoric acid was dissolved in a. mixture of 87 parts by weight of toluene and 39 parts by weight of ethyl alcohol. 12 parts by weight of finely powdered barium oxide was added to the solution and the mixture heated at about 40-60 with stirring until it was neutralized. 87 parts by weight of toluene was then added and the solution filtered to remove traces of inorganic barium salts. The filtrate was then evaporated under reduced pressure to remove the solvent. The resulting barium salt of di(wax phenyl) dithiophosphoric acid was an amber-colored liquid easily soluble in lubricatin oil.

What we claim is:

lAZompounds having the general formula R-O s in which R is a parafiln wax substituted aryl radical said wax substituent containing at least 22 carbon-atoms, M is a, member of the group consisting of hydrogen and basic salt-formin groups and n is the valence of hydrogen or the basic salt-forming group.

2rCompounds'having the general formula R-o s- 2 in whigh R is a paraffin wax substituted aryl R -'-CB-S O-R in which R is a paraffin wax substituted aryl radical said wax substituent containing at least 22 carbon atoms.

5. Compoundshavingthe general formula a-o s s O-R x RO/ SMg-S \0-R *'inwhlch R is a paramn wax substituted aryl radical said wax substituent containing at least 22 carbon atoms. 6. Compoundsd1aving the general formula in which R is a pafaflin wax substituted phenyl radical said wax substituent containing at least 22 carbon atoms, and M is-an alkaline earth.

8. Compounds having the generaljormula in which R is a parafiin wax substituted phenyl radical said wax substituent containing at least 22 carbon atoms.

9. Compounds having the general formula in .which R is a 'paraflin wax substituted phenyl radical said wax substituent containing at least 22 carbon atoms. 5

11. A method of preparing paraflln wax substituted diaryl dithiophosphoric acid which comprises heating paraflin wax substituted hydroxyaromatic compounds said paraiiin wax substituent containing at least 22 carbon atoms with P285 at temperatures within the range 130- 160 C.

12. A method of preparing paramn wax substituted diphenyi' dithiophosphoric acid which comprises heating parafliin wax substituted phenols said paramn wax substituent containing at least 22 carbon atoms with P285 at temperatures within the range 130-180" C.

13. A- method of preparing paraiiln wax substituted diaryi dithiophosphates which comprises heating paramn wax substituted hydroxyaromatic compounds said paramn wax substituent containing at least 22 carbon atoms with P285 at temperatures within the range 130-160 C. and neutralizing the resulting product with a salt-forming base.

14. A method of preparing paraflin wax substituted diaryl dithiophopshates which comprises heating'paraflin wax substituted hydroxyaromatic compounds said paraiiin wax substituent containing at least 22 carbon atoms with P235 at temperatures within the range 130-160 C. and neutralizing the resulting product with barium oxide.

15. A metliod of preparing paraflin wax substituted diphenyl dithiophosphates which comprises heating paraflin wax substituted phenols said paraflin wax substituent containing at least 22 carbon atoms with P285 at temperatures within'the range 130-160 C. and neutralizing the resulting product with a salt-forming base.

16. A method of preparing paraflin wax substituted diphe'nyl dithiophosphates which comprises heating paraflin wax substituted phenols said paraflin wax substituent containing, at least 22 carbon atoms with P285 at temperatures within the range 130-160 C. and neutralizing the resulting product with barium oxide.

' EImR. W. COOK.

WIILIAM D. THOMAS, Jr. 

